Many electronic devices use power supplies. Such power supplies may be external or internal to the electronic device. The power supply may include a voltage regulator. The voltage regulator may be configured to generate a constant output voltage. The output voltage may be a direct current (DC) voltage. The output voltage may be generated using an input voltage. The voltage regulator may be configured to attempt to maintain a constant output voltage despite changes in input voltage or in a load attached to the voltage regulator. If the output voltage is less than the input voltage, the voltage regulator may be said to be implemented as a buck converter or operating in a buck mode. If the output voltage is greater than the input voltage, the voltage regulator may be said to be implemented as a boost converter or operating in boost mode. The voltage regulator may be implemented as a buck-boost converter, wherein it may operate in buck mode, boost mode, or in a buck-boost mode wherein both buck and boost components therein are in operation.
Capacitance may form on the input or on the output of a power supply. Some solutions may dissipate charge built up in this capacitance through linear solutions, such as a constant current discharge or a resistor discharge. However, such solutions may generate significant thermal energy, requiring additional thermal dissipation solutions to handle the thermal energy generated by the dissipated capacitance. Other solutions may include recuperative solutions, where current discharging the charge accumulated in the output capacitance is routed from the output capacitance to the input capacitance, or vice-versa. However, such solutions are complex since there may be a wide variance in input voltage based upon the capacitances. Still other solutions may include loss switching, wherein a low-side output switch of the buck-boost voltage regulator may be switched on and off to dissipate charge accumulated in the output capacitance. However, such solutions may require a very low frequency to allow an inductor of the voltage regulator to charge and discharge without becoming saturated.
Embodiments of the present disclosure address various shortcomings of other solutions to discharge the charge accumulated in input and/or output capacitances of voltage regulators as discussed above. Embodiments of the present disclosure may include power regulators that reduce the area on a die needed to dissipate power. Embodiments of the present disclosure may avoid the need for close-coupled thermal protection. Embodiments of the present disclosure may avoid significant increases in input voltage, operate without saturating the inductor. Embodiments of the present disclosure may operate without requiring additional pins on a semiconductor device implementing the power regulator.